im going to be doing a bank of injectors this set of days off, can anyone tell me what the latest injector hold down torque value is? in searching im finding 24 ftlbs as an old value, 26 a bunch, a couple 28, and holders said 31 on the phone.

im going with motorcraft remans, my sister inlaw works at a dealership and can get them for me at a slight discount. im doing the driver bank because when i had a cracked tip a few months ago the mechanic did a contribution test and 2 was low and had thrown a code in addition to 7 which is the one that failed. he recommended at the least a new #2. i dont feel like going back in anytime soon so im doing all 8, just starting with the driver bank.

thanks in advance!

 

I am sure someone will confirm but remember to use the extra long torx or YOU WILL increase the chances of cracking the plastic pieces on the injector

 

In the box will be the torque specs, 24lb-ft is for the 18mm heads with the T-40 injector screws, 25.8lb-ft for the 20mm heads with the T-45 injector screws. I'd stay with those since the heads have a habit in some situations of cracking above the injector cup, right where the screw is. But hey, that's me.

 

Holder's is saying 31 ft-lbs for your '03??? Were they aware that it is an '03?

I am stunned - for the reasons Jack posted.

 

yes they were. ive done a ton of reading on this, but if there are torque values in the box then ill just go with what they say in the box. like i say, ive read 24 for the t40, 26 for the t40 and t45, 28, and 31. ill just follow what the instructions in the box say if they state a torque value.

 

yep, already have a set, appreciate the suggestion. i have some that i bought for the hand controls on my bike after i boogered up my black switch housings.

 

I have to ask - you sure they didn't say 31 Newton-Meters (NM). That is 23 ft-lbs .... a lot closer to the 24 ft-lbs that International and Ford say for the 03 model year.

That said, 24 ft-lbs is 32.5 NM, so nothing matches well.

 

I’ve been recommended by many independent sources torque the injectors over the OEM values. The guy who sold me my ford injections said he does them all to 30 lb/ft and had occasional come backs with 24 lb/ft that had signs of leakage passed the little copper sealing washer.

 

Looks like WDI says 31 ft-lbs on the T40 hold-downs also (2:12 time stamp). I just wouldn't do that on a truck of mine. Ford cites over-torquing as a possible reason for heads cracking. TSB 08-23-8 and the training video that is no longer available (mms://multimedia.ford.com/fordstar/66920.wmv)....citing thinner castings in the head at the middle 4 cylinder locations i the pre-commonized heads.

Also, I would use a longer torx bit as suggested above.

 

I can muddy the waters up pretty well here with this subject. But it is a subject that has bothered me for probably 15 years.

We have the two torque specs for the different head/injector hold-down designs, and then we have people who come up with more is better. And I've seen that with suppliers I don't think have any engineering training. Not that you need to, but they don't seem to understand bolt strength and stress. Holder's may be saying 31, but it's an antsy point to me, not because of the bolt but the heads.

The two designs of the holders change the clamp down location and the leverage to the injector. But the change to the torque value is about that relationship, not the commonly believed "Ford upped the torque for more pressure". It might be the same hold-down pressure - AT THE INJECTOR. I never had the two heads to play with; I have the weird 20mm "Service Head", which has the casting changes but drilled so the older clamps could be used.

Maybe it would have been better to take this image with the bolts in alignment instead of the tip of the clamps.





But the other thing to note about the injector hold-down bolts is they are the extreme strength 12.9 grade, with an R which means the threads were rolled after strengthening, so the threads are very strong.

I could do a long explanation about this data, but the bolts are nowhere near a worrisome stress level for the bolts, even if you use a higher-than-specified torque value. The actual clamping load changes if the threads are lubed or dry, another factor. But, you could go higher than many people talk about, and you will not yield the bolts. But that's not my concern.​​​​​​​



Whatever the clamping force is, that is also the pull-up force to the head. And it's right where the injector bores have known to crack, specifically cylinders 3 and 5 on the passenger side. As discussed in other threads, there may be other reasons why that side tends to crack, but the uplift force from the injector's hold-down is probably a factor. I'm more comfortable if the heads are the "communized" or 20mm heads; as Ford stated, the heads were strengthened in that area. I'm just concerned about the injectors' torque values often thrown around. There are stories of people who have torqued over spec and have been fine. But it's something I'm not comfortable with.

Now I need to find the head image ......

 

I'm just going to use screen grabs from my video. Everyone can do what they want.

I just don't need to tension my heads in the critical injector area with an additional 1,500 lbs pull-up.

 

and this is why im going on over 20 years as this being the best ford forum on the web. i really appreciate the input and the explanations, you guys make this page what it is.

 

Just be sure to blow all the oil from the hold down bolt holes.

 

and here is the winner for the most important step in doing injectors that get overlooked.

 

yes sir, was planning on hitting them with the old brake flush and air wand.

i have to ask, are those torque specs for a lubed bolt or dry?